As most of you know I'm still new at this and I need some help. I'm getting ready to put my quilt together. I know how to sandwich but I can't find any info on what size the back and batting should be compared to the top. I haven't decided if I'm going to put a 2" binding around it or use bias tape, so I need to know what to do for both of them. All I have been able to find when I google is how to sandwich. It says nothing about how much extra fabric and batting I need.